Interestingly, flow cytometry analysis of pre-treatment peripheral blood from a cohort study of 188 ICB-treated melanoma patients and 94 ICB-treated urothelial cancer patients with the aim of identifying blood-based biomarkers showed that the presence of LAG-3+ and LAG-3+CD8+ T cells in peripheral blood was shown to be associated with poorer survival outcomes in ICB-treated melanoma and urothelial carcinoma (49). This evidence concerns the gene CD8A and urothelial carcinoma.